Mobile devices have become an integral part of an individual's life both at business and at home. Like desktop and laptop computers, there are now available rich applications to run on mobile devices.
Unlike desktop, and far more than laptop computers, mobile devices are constantly moving in and out of areas network connectivity. Additionally, these mobile devices, and in particular mobile phones, are generally always on and are constant companions of their users.
Typically, most of these devices are optimized to primarily work with one kind of wireless network such as a CDMA network, a GSM or UMTS network, a Wi-Fi network, and the like. The network connections established with these mobile devices, however, is not constant.
For example, mobile phone users travel in and out of zones of connectivity all day long. A person may be going above and below ground and entering in and out of buildings all day long. This movement results in losing network access from a few seconds at a time to longer periods of time as they move from point to point. Not only may the network access may be intermittent, the types of available networks may vary from location to location.
Many locations also have “dead spots” where network connections do not exist. For example, dead spots may occur in the centers of buildings as well as in elevators. Additionally, many modem workplaces offer their own private wireless networks (e.g. Wi-Fi) in addition to the public mobile phone networks. Switching between these different network options and dealing robustly with the temporary absence of network connections is problematic for software applications running on the devices.
Some locations are configured to prevent access to wireless networks as matter of policy. These restricted areas include locations such as: airplanes; government embassies and offices around the world; as well as other secure areas. The end result is that ubiquitous connectivity for mobile devices does not exist. This is markedly different from desktop or laptop connectivity. Connectivity may be always near a user, but it is often missing at a user's exact location.